In recent times, as information communication technologies and broadcast technologies have been increasingly developed and combined, a user can freely view desired digital broadcast data from anywhere he or she wishes at any time. For example, the user can view digital broadcast data at a fixed place at a fixed time, can view the digital broadcast data while in motion, or can view the digital broadcast data at a desired place at a desired time.
Particularly, an S-SMB (Satellite Digital Multimedia Broadcasting) service has begun in the Republic of Korea since May 2005. It is expected that a variety of digital broadcast services will be widely used throughout the world. Conventionally, many developers have conducted intensive research into digital broadcast technologies associated with fixed- and mobile-receivers, such that a variety of digital broadcast services for use in the fixed- and mobile-receivers are being widely used throughout the world.
For example, a DAB (Digital Audio Broadcasting) service, a DVB-T (Digital Video Broadcasting-Terrestrial) service, and a DVB-H (Digital Video Broadcasting-Handheld) service are being widely used in Europe. A Media FLO (forward Link Only) service developed by Qualcomm Corporation is being widely used in the United States, and a DMB (Digital Multimedia Broadcasting) service is being widely used in the Republic of Korea. With the widespread use of the above-mentioned digital broadcast services, terminal users can receive radio-, TV-, and teletext-broadcast services of CD-level high-quality from anywhere at any time.
In addition, users may receive not only conventional music- and TV-broadcasting services, but also other application services associated with digital broadcast technologies. The following are examples of services using the related technology: a TPEG service for providing users with traffic information in real time; a GPS service for recognizing location information of a vehicle or human being by measuring three points using a satellite; an MP3 service for transmitting CD-level audio signals received in a mobile digital broadcast receiver or a digital broadcast receiver of a vehicle to an MP3 player, such that the user can freely listen to desired MP3 music data from anywhere at any time; a slideshow service for providing a still image (e.g., a JPEG image); an R-commerce service; and a BWS (Broadcasting Website) service, etc.
As described above, the digital broadcast service can provide users with a variety of multimedia content broadcast services (e.g., education-, drama-, news-, sports-, game-, music-, and movie-contents). Therefore, the user selects desired multimedia content data from among the aforementioned contents according to his or her preference, such that the user can create a variety of new contents by editing the received content data.
Particularly, a conventional slideshow service has been designed to transmit still images from a broadcast station to the user, such that the user cannot actively construct a desired slideshow. In the meantime, the digital broadcast may comprise video data. Since the video data has a large amount of data, data compression is executed on the video data, such that the compressed video data is recorded in or transmitted to a recording medium. A representative image compression method is a Motion Picture Experts Group (MPEG) encoding method commonly defined by ISO and IEC. Also, the ITU H.261 and the ITU H.263 may also be used as other image compression methods.
In recent times, in order to obviate limitations of conventional motion picture encoding standards (e.g., H.261, H.263, and MPEG-4 Part 2), the PEG-4 Part 10 AVC (Advanced Video Coding) standard and the ITU-T Rec.H.264 standard have been newly proposed. The MPEG-4 standard has defined an I-frame (Intra-Picture), a P-frame (Unidirectionally Predicted Picture), and a B-frame (Bidirectionally Picture).
The I-frame is a reference picture of a video, and acts as a basic unit capable of constructing a picture. In other words, the I-frame is a picture capable of being encoded by corresponding picture information, and is used for random access. The P-frame is a picture created when the past picture is predicted. The B-frame is a picture created when the past picture and the future picture are predicted.